A shipwrecked sailor is stranded on
a small desert island with no fresh water to drink. She knows she could last
without food for up to a month, but if she didn't have water to drink she would
be dead within a week. Hoping to postpone the inevitable, her thirst drove her
to drink the salty seawater. She was dead in two days. Why do you think drinking
seawater killed the sailor faster than not drinking any water at all? Today we
explore the cause of the sailor's death. We'll prepare solutions of salt water
to represent the sea, and we'll cut up slices of potato to represent the sailor.
Potatoes are made of cells, as is the sailor!

Objective:

The concentration of solute in a solution
will affect the movement of water across potato cell membranes.